Professor Andrew Warren,Department of
Geography, University
College London

Desertification
is difficult to define in measurable terms, and many of the assertions made in
its name have proved alarmist. In large measure, the problems arise because
environmental damage is judged differently by different cultures at different
times. For this reason, evidence for overgrazing, desert advance, climatic
change, the fragility of dry ecosystems, and the effects of increasing
population have all been elusive.Nonetheless, the term has an interesting history, dating from fear about
the spread of the desert in the US midwest
and in West Africa, which dates from the early years of the 20th century.The severe desiccation of the 1970s and 1980s
revived the term, and international interest in it.“Desertification” is best seen as a portmanteau word for serious
environmental problems in dry countries, many of which are among the poorest on
earth.One problem is drought.Although many ecological and social systems
have evolved to deal with drought, societies in rapid transition are
vulnerable.Another problem is
“desiccation” (the longer term drying out).There have indeed been long droughts or dry periods in recent history
and they have caused havoc in many societies.Finally, there is “degradation”.One form of degradation, overgrazing, is now thought to be far less of
an issue than it was twenty years ago.Soil erosion is another form of degradation, and although probably very
serious in some of the drylands, not enough is known
of its drivers.For all the difficulties
with the term, it has a future, if only in the United Nations Convention to
Combat Desertification, to which many dry countries have signed up, and which
will require planning into the early 2000s.

The importance of desertification for the peoples of the
world’s drylands should not be underestimated, despite considerable
uncertainty about its meaning. Firstly, the term, for all its problems,
envelops a set of processes, sometimes listed as drought, desiccation and degradation, that pose very real and severe challenges to drylands, and have strong knock-on effects on society.Secondly, desertification language is deeply
entrenched in policy circles and in the current UN Convention to Combat
Desertification (CCD), and will inevitably continue to inform the financing of
development interventions in drylands.

1. History and Definitions

The “Agenda 21” document
of the 1992 United Nations Conference on Environment and Development (UNCED)
defined desertification as “land
degradation in arid, semi-arid and dry sub-humid areas resulting from various
factors, including climatic variations and human activities”. The
processes of degradation were said to be soil erosion, nutrient depletion,
crust formation, salinization, reduction in pasture
and agricultural productivity, loss of biodiversity, and reduction in
vegetation coverin susceptible drylands. Of course, uncertainties abound: the
circumstances fostering reversible or irreversible change; the resiliency of
different semi-arid environments; the different roles of natural and
anthropogenic driving forces; and the synergies among these elements.

Scientists were
exercised as early as the 1920s with the ‘the advance and spread of the desert’
in Africa.It was then that France began
the first studies of the process in West Africa, finding evidence of mobile sand
dunes, human fossil remains in now-dry areas, and declining annual rainfall. It
was concluded that the Sahara had grown, and was still growing, owing to poor
land management, which had worsened under the colonial regime.

These early judgements
preceded what environmental historians are now discovering to have been a much
more traumatic event, the American ‘Dust Bowl’ of the 1930s.Sears’sDeserts on the March(1935)
evoked accusations of widespread anthropogenic degradation. He and others
believed they also had evidence of widespread environmental degradation in the
dry lands of Europe, whose cause, as in the Midwestern states, was
also thought to be mismanagement.With
these narratives very much in mind, E.P. Stebbing, a
forester, identified the causes of degradation in British West Africa to be
shortened agricultural fallow periods, shifting agriculture, and overgrazing (Stebbing, 1935). An Anglo-French Forestry Commission [which
went to look at forestry in the European colonies] toured the Niger-Nigeria
border in 1936-7, and their conclusions were far more circumspect.They saw degradation as place-specific and
treatable. Yet a member of this Commission, the influential French botanist AugusteAubréville, held to the
‘desert advance’ hypothesis, and first used the term ‘desertification’ in 1949.

In dryland
Africa, severe drought and famine in the 1970s, following decades of good
rainfall, again revived the desertification debate, with depressing reports of
desert advance appearing in scientific publications and the media. This alarm
stoked the United Nations Conference on Desertification (UNCOD), held in
Nairobi in 1977. UNCOD, and the National Plans of Action agreed by each
participant dryland country at that meeting, still viewed people as the
main agents of desertification.

2. Current research

Research into the links
between climate, management and degradation has taught us a great deal since
the 1970s.Since then, many detailed
studies of human-environment interactions at the local scale have been carried
out in the drylands, spurred on by advances in
climatology, soil science, botany, geo-informatics, agronomy, and the social sciences.

This research,
conducted by numerous scholars from the natural and social sciences, offers a
longer-term view of what happens as rainfall fluctuates, or when soils are lost
and gained. More generally it has examined the complexity of the linkage
between resources and people in the drylands, and the
role of adaptive local resource management. Above all, it is now possible to
challenge notions about an equilibrium state or “carrying capacity” in these
environments and from there to challenge the desertification narrative with
better, if still imperfect evidence.

Yet laying the
desertification discourse to rest is difficult. At least six themes remain
essential elements of the desertification debate.

Advance of desert. Large-scale Saharan expansion has not been proven within
the period of the historical record.Desert advance in the Sudanhas been asserted since the 1930s, but
Helldén (1991) found no such evidence from satellite
imagery, settlement histories, sand movements, and degradation conditions
around boreholes. The current view is that the Sahara expands and contracts
periodically asrainfall varies. Desert advance (as in the severe drought of
1984), and localised degradation, is usually short-term (Tucker et al. 1991; Nicholson et al. 1998).

Resilience of dryland ecosystems
and land-use systems. Degradation
is, therefore, usually localised and ephemeral [short-lived], largely a
function of the complexity of relationships that exist between humans and natural systems. Semi-arid ecosystems, far from
being fragile, exist in a range of semi-permanent ‘states’ dictated by
disturbance, drought, fire or insect attack; they are well adapted to these
forces.Similarly many indigenous
management systems redistribute nutrients, plants, grazing pressure and water
to create ‘enriched’ patches in the landscape.

Influence of grazing and livestock. The UN Atlas
of Desertification (1992) asserted that 58% of soil erosion in dryland Africa was the result of overgrazing by livestock,
lending support to Garret Hardin’s ‘tragedy of the commons’ hypothesis, that
said that too many herders all using the same piece of rangeland would tend to
degrade it through their own selfishness.Such figures gave way to more conservative estimates in the latest
version of the Atlas (Thomas and
Middleton, 1996).There is now greater
confidence about the heterogeneity and patch dynamics of pastoralist grazing
strategies so critical to many drylands. Less existing
vegetation is not necessarily worse vegetation in terms of biodiversity. It is
difficult to overgraze in a dynamic non-equilibrium system, dominated by annual
grasses, where the external forces like drought are more powerful animal
numbers as influences on rangeland quality.

Effects of increased population in rainfeddryland agricultural
systems. No necessary
Malthusian link exists between elevated population levels and resource
degradation. [see earlier indv
103 lecture] . Indeed, because there is
often an incentive for rural people to invest in anti-degradation measures in
these circumstances, more people (and labour) may mean less erosion, and the
initiation of compensatory risk management strategies.

Soil erosion and fertility decline.Although topsoil erosion does occur in drylands
and soil is blown or washed away, these processes do not themselves
necessarily result in degraded landscapes. Soils are often replacable
or may be very deep, and can accumulate down-slope or down-wind where they may
be more valuable to local people. Indigenous dryland
soil conservation systems are impressive. Yet even after decades of research,
soil erosion and the values placed upon it by society are very difficult to
measure.

Climate Change.There are two issues here. Charney & Stone (1975) suggested that devegetation might induce regional drought —bare soils are cooler because they
reflect more solar energy and cool surfaces discourage rainfall.This hypothesis remains disputed.Current research provide
strong evidence that changes in surface characteristics, including vegetation,
affect local and regional rainfall patterns significantly. Some climatologists
however, find little evidence in this claim as registered in the coarser scale
climate record (Williams & Balling, 1996). As well, potential global
warming and the ENSO (El Niño-Southern Oscillation)
will have differential, and as yet uncertain effects
on certain drylands, with the majority of current
models suggesting increased rainfall and temperature variability in Africa.

3. Desertification Policies

Research, policymaking
and interventions are strongly linked. For example, when scientists pinpointed
advancing deserts, the policy response, was ‘plant green belts!’ [around the Sahara]. Roosevelt commissioned a study of a massive green belt of
trees between Texas and North Dakota after the Dust Bowl. Stebbing
recommended much the same for Africa, and UNCOD proposed a circum-Sahara green belt.The Algerian government actually began
planting trees, employing conscripts to do so.Where scientists believed that herdsmen or farmers were irrationally
causing degradation, policy-makers and government officials prohibited goats,
the destocking of herds, the prohibition of tree
cutting or grass burning; or on a much more massive scale, they enforced soil
conservation programmes.

Anti-desertification
measures have been international in scope. A suite of international
institutions materialised after the great Sahelian
drought of the late 1960s and early 1970s. First, the United Nations Sudano-Sahelian Office (UNSO) was charged with combatting drought, later taking on desertification issues.
It was later joined by the UN Environment Programme and the FAO in these roles.
Scientific panels and advisors produced a “veritable sandstorm of literature”
(Mortimore 1998:23) on the complexities of drylands.
In general, the prognosis was gloomy: 10% of the earth’s surface was human-made
desert; and the process would continue.Desertification became enshrined in international policy.

African states absorbed
some of UNCOD’s recommendations from the late 1970s,
although they were held back by poor funding. Projects were initiated, most
designed to arrest soil erosion. Some were implemented without adequate local
consultation or participation. Many, like the GERES project in Burkina Faso where bulldozers were used to create earthen
bunds across many slopes to slow water runoff, actually increased erosion
rates.Fuelwood
supply projects [to plant loads of trees as plantations] and the drastic destocking of indigenous pastures [reducing livestock
numbers] failed for the lack of local complicity.

Unforeseen
ramifications followed in the post-UNCOD, post-Sahelian
drought era. In Niger, West Africa, proposals for green belts resorted to authoritarian measures for
implementation, for in local eyes, as in the eyes of scientists today, they
were deeply irrational. In similar vein the military rulers of Mali banned the burning of forests and grasslands to
release nutrients to the soil, this was counter to local know-how about the
enriching powers of fire on pastures. In many countries, the cutting of fuelwood was unnecessarily proscribed. Most disturbingly,
the characterisation of African pastures as "overgrazed" came to
infest writing about them.Attempts were thus
made to reduce the numbers of livestock; to privatise grazing lands; and even
to replace herding the commons with systems based on European and North
American models (Warren 1996). The desertification threat was used to justify authoritarian
control over natural resources and land-use practices.

A broadened, perhaps
softened conception of desertification suggests a new range of policies that,
given sensitive application, may prove more successful because they are more
trusting of dryland populations and more aware of
ecological diversity. New initiatives are based on a better understanding of
the three main issues in dryland management: drought,
desiccation and degradation.Drought is
common currency among dryland folk.It may not be welcome, but people clearly
have a portfolio of coping strategies to deal with it, and reflexive management
that constantly adapts to an ever-changing situation. These indigenous systems
are now being supported, rather than replaced or obstructed. Desiccation is
known to have been frequent in the history of human occupation of drylands.Large-scale shifts in livelihood practices occur under progressive
aridity, but Sahelian drought illustrates that
relief, restocking and resettlement are necessary when this happens.Degradation requires a range of
responses.Rich repertoires of
conserving indigenous techniques exist, some – like permeable contour bunds -
already improved through hybrid experimentation between farmers and scientists.
Drylands and dryland
peoples and their economies are heterogeneous.Policies increasingly aim to protect
this diversity, rather than erase it. Greater clarity of land tenure security
is needed, and rangeland areas require special forms of collective management . In brief, livelihood security is essential to
good conservation.

4. The Convention to Combat Desertification

UNCED, the Rio Conference, held in Rio in 1992, breathed new life into the unpopular, almost
forgotten ‘desertification’ concept. Fortunately,
Chapter 12 of UNCED’s Agenda 21 document is far less
alarmist in its tone than UNCOD’s recommendations of
fifteen years earlier, adopting some of the findings and views of the new
research reported above. For example, climate change is now seen as a major
contributor to desertification, and drought preparedness, education, and strong
local participation are now stressed.

The Convention to
Combat Desertification (CCD) came into force on 26 December 1996 (see http://www.unccd.ch/ for full
details and current negotiations). Although there was scepticism about this new
international effort, non-government organizations and other actors from
developing countries had a relatively strong involvement in drawing up the
Convention. The various CCD components are legally binding on the countries
that sign up to it, and include detailed plans for Africa, Asia, Latin America, the Caribbean, and the northern Mediterranean. Almost 160 countries had ratified the
Convention by September 1999. The focus has moved to implementation, despite
significant questions about who pays, coordinates, and monitors the activities.
By 2000 National Action Plans were drawn up by most dryland
nations, but progress is hampered since there is no international CCD
implementation fund available, so many of them are really just paper documents.

5. Conclusion

In the absence of well
adapted technologies, life in drylands is harsh.That degradation of these lands follows from
social and climatic processes is not
in dispute. But whether degradation amounting to desertification of the
magnitude assumed in the early debates, or even in the recent Convention [CCD],
has been strongly challenged by the research and other communities.
Nonetheless, desertification remains
a powerful narrative that has captured the imagination of certain policy
makers, governments, and scientists, and it has persisted with peaks and
troughs of interest since the 1930s. Its power is problematic, since
“the search for accuracy appears to be vulnerable to generalisation,
over-simplification and distortion for political or funding purposes”
(Mortimore1998:33).
Desertification
has certainly served specific constituencies quite well: -

national governments
seeking to extend their control,

international
bureaucracies seeking legitimacy,

and scientists seeking
research funding.

Tackling the various processes that the term
desertification subsumes is a major challenge, given that dryland
populations suffer the impacts of droughts and desiccation, and need to exploit
land, water, and timber resources in ways which often result in degradation. As
an explanatory term, however, desertification has been used too broadly and too
loosely, and this has been counterproductive.